1. Field of the Invention
This invention relates to roll-type compressing apparatus and more particularly to roll presses utilized in forming briquettes by hot or cold pressing coal char, reduced iron ore and other substances.
2. Description of the Prior Art
Roll presses used as briquetting apparatus usually include a central arbor upon which are mounted a plurality of replaceable segments having surfaces formed therein for shaping material to the desired briquette shape. Since such apparatus may be employed with material at relatively high temperatures, it is desirable that provision be made for thermal expansion of the segments during use. Moreover, where such apparatus is used at relatively high temperatures it is necessary to provide suitable cooling for the mounting arbor and the segments mounted thereon. Further, it is desirable that such segments be held firmly in position while still allowing for the necessary thermal expansion. Should any segment become broken or distorted during use it is also desirable that provision be made for relatively easy replacement of such segment.
Prior art briquetting machines have had a number of disadvantages. For example, some machines have included for cooling purposes a plurality of spaced passages extending in a generally axial direction through the arbor and have included at the ends thereof manifold structures secured to the arbor for providing communication between the spaced passages. Unfortunately such constructions provide a source of leakage at the manifolds, particularly as a result of thermal changes and stresses induced in the structure during the forming of briquettes. Further, in some such structures the mounting of the segments is such that the cooling passages are not sufficiently close to the segments to provide optimum cooling thereof.
In other prior art structures the arrangement for mounting the segments significantly limits the thermal expansion thereby causing undesirable build up of stresses in the segments.
In other prior art structures a relatively complex structure including arrangements for mating of cooling passages is employed for mounting the segments so that removal and replacement thereof involves a relatively lengthy and complex procedure.
By the present invention a roll press for forming briquettes is provided wherein the briquette-forming segments are easily and securely mounted on the supporting arbor, adequate provision is made for thermal expansion in a controlled manner, and provision is made for effective cooling while still minimizing the possibility of leakage of the cooling fluid. Provision is also made for securely mounting the segments while still simplifying the machining thereof and while permitting relatively easy replacement thereof when necessary.